Boston University Steers Qubit Phase With Tailored Drives

Controlling how quantum systems interact with their environment remains a key challenge in building strong technologies. A team at Boston University has revealed a new method using periodic driving, repeatedly applying an energy pulse, to manipulate the geometric phase within open quantum systems. Manipulating periodic energy pulses affects quantum systems interacting with their surroundings. Repeated application of these ‘drives’ controls changes to fundamental properties called geometric phases within complex systems exposed to environmental noise.

This technique differs from previous methods relying on static adjustments; it offers greater adaptability in managing external disturbances affecting open quantum systems. The researchers have detailed how precisely timed energy pulses manage subtle changes in a quantum system’s state, similar to tracing a path around an object where the final position depends not just on starting and ending points but *how* you got there. These ‘geometric phases’, key for potential technologies like quantum computing, are easily disrupted by environmental noise affecting open quantum systems, those interacting with their surroundings.

The team investigated manipulating these geometric phases within such vulnerable systems using periodic driving, repeatedly applying an energy pulse to influence interactions. To quantify this control, they introduced a method separating the effects of both external drives and inherent dissipation from the system; understanding whether drive parameters enhance or suppress environmentally-induced distortions is vital. Precisely tuning these pulses offers strong protection against decoherence, paving the way for more stable quantum devices.